Detection Mode:

Fill the transparent region surrounded by lines, if the pixel's transparency is in range of
[Transp diff.] parameter these pixels are treated as transparent.

- Transparency (Fuzzy)

Fill the transparent region surrounded by lines more fuzzyly, if the pixel's transparency is
in range of [Transp diff.] parameter these pixels are treated as transparent. This mode is
sometimes more useful for roughly sketched image, but if the image is too rough this may be
not so enough.

Color Difference

Fill the region these colors are in range of [Color diff.] parameter with the clicked
pixel's color.

Target:

- Working Layer

Set current selected layer as detection target.

- Selection Source

Set the layer with [Selection Source] option (in layer list) is checked as detection target.